[time-nuts] Racal-Dana tactile switches
GandalfG8 at aol.com
GandalfG8 at aol.com
Sat Apr 5 21:32:06 UTC 2014
In a message dated 05/04/2014 22:10:50 GMT Daylight Time, bix at jimbixby.com
I finally had to dive into my Racal Dana 1992 counter, after it had
developed several bad switches. I found that through-hole 6x6mm tactile
switches with four leads will fit in the counter pcb holes diagonally.
is, if you trim off the leads from two opposite corners, the other two
are very close to the required distance to go into the existing pcb holes.
just ordered some of these switches from ebay with a long plunger that
to be perhaps 2mm round. I'm going to drill holes into the back of the
existing keycaps to be a press-fit to the plunger on the new switches. I
think it will all hold together. If this works, it is a cosmetically and
functionally perfect solution. I'll report back after I've tried it.
The switches I picked are 6x6x10.5mm Tactile Pushbutton Switches,
ebay item 161008571229,
Below is a copy of a post I made to the list in April 2012, with a link at
the end that you might find useful.........
I made a successful repair of a Racal 1991 counter that I originally
bought as a spares unit, the original switches and switch caps had already
removed and discarded, but decided after all that it was too good to just
use for parts, especially as all that ever seems to fail anyway are the
As I believe others have also suggested I found that 6mm square tactile
PCB switches could be modified to fit in place of the original Racal
Refitting the original switch caps wasn't an option for me, but whilst
trying to devise some convenient method of operating the normally very
PCB switches through the front panel I came across some switches on Ebay
with extended actuators.
Using a switch with an overall height of 13mm allowed the actuator to
protrude approximately 3mm through the panel and this works remarkably
It's obviously not totally ideal, one downside for many would be that the
keypad numbering is normally only on the switch caps, although I was lucky
with this unit and the numbers were part of the panel markings, but it did
restore the 1991 to being a perfectly usable counter.
However, given that most users contemplating something similar would
probably still have the original switch caps, and that it shouldn't be too
difficult to refit these to the longer actuators, I think such switches
provide at least one answer to the problem.
Anyway, I've written up a few notes to go with some photos I took whilst
fitting the switches to my unit and have uploaded these to Rapidshare just
in case anyone might be interested......
Please feel free to share or bin this as you think fit:-)
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